Rotary force-feed piston pump



Feb. 18, 1930. HQ JoHANsoN ETAL 1,747,245

ROTARY. FORCE FEED PIvSVTON PUMI Filed Feb. 12, 1929 2 sheets-#sheet f 1Pefenteel Feb. 1s, 1930 UNITED STATES PATENT@ ori-ICE `ROTARY FORCE-FEEDPISTON PUMP Application led February 12, 1829, Serial No. 339,406, andin Germany January 81, 192,8.

This invention relates to rotary piston force feed lubricating oil pumpswith a plurality of pistons whose stroke is separately variable, andhaving several force feed points and 5 which are especially suitable foruse in motor vehicles.

There are already known piston pumps in which the piston, while the pumpis in operation, is rotated around its longitudinal axis and while itrotates is at the same time displaced axially against the action ofaspring. lhe axial displacement produces the movements of the piston. Themovements of the piston may be determined on the one hand in the knownmanner whereby at one end of the hollow piston an annular ring face isformed as a cam face which, during the rotation of the piston isfollowing in a curve which is formed to correspond with the length ofthe stroke. On the other hand, the said curve may also be provided onthe annular ring face of the piston by forming this in a plane ofsection taking an inclined position to the axis, and which for instancemay bear on a fixed stud, so that in this manner the move.

ments of thepiston are produced, or else the curve is formed by acorresponding groove which has been formed in position and in whichengages a gudgeon pin. In each of the first named instances, acompression spring which is positioned Within the hollow piston iscalled upon lto press the piston always against its curve in order toproduce the movement of the piston, whereas, when the piston is formedwith the groove drilled into the same, the spring may be omitted,because in such a case, by reason of the engagement of the gudgeon pinin the groove, the piston is positively guided b eachside of thegroove'.

A force feed lubricating oil pump which is constituted in this mannerwill always deliver an equal quantity of oil. Sometimes it will,however, be necessary to vary the quantity of oil delivered which willprove of especial advantage in those cases in which the piston pump, inthe shape of a small oil pump, is designed to serve for the oiling ofthe cylinders of combustion engines. The variability of the quantity ofoil delivered will permit the use of the same size pump for combustionengines of'varying size, seeing that the quantit of the oil deliveredmay always be adjuste in conformity with the supply of oil required bythe cylinders of the combustion engines, so that an excessive oil supplyis definitely avoided which will, of course, result in a very economicaloil consumption.

` Pumps of the usual type now known tothe art possess as a rule, onlyone or at the most two force feed points. In the main, however, we onlyfind that type of pump in which one suction point and one force pointare crowded into a narrow space, in a convenient place of the engines,asfor instance in motor cycle engines.

At the present stage of engineering and of the construction ofcombustion engines, and especially of those which are designed to servefor use in motor cycles, the provision of only one force feed point forsupplying the oil in the cylinder of a combustion engine will not, as arule., be suliicient, for there are several other places in a motorvehicle which require lubrication, as for instance, the chain, or thefaces of the cams in motor vehicles with upper valve motion. With thepresent form of pump having one force feed point only, one or more pipesof suitable diameter are branched ofi for thepurpose of supplying theabove mentioned oil consuming places with oil, which is after all onlyan emergency arrangement, because Whenever one' has to deal with a totaloilsupply which is of some importance, this arrangement will prove to beunable to supply all the oil consuming places with that quantity of oilwhich thev absolutely require and it will thus happen that one or theother of these oil consuming-places will be supplied with oilinadequately.

Therefore, we have designed rotary piston pumps with several force feedpoints which are all subject to the action of the moving l piston byproviding for instance the piston at both ends with suitable slots orgrooves which are drilled into the same and which produce the action ofsuction and of forcing and by connecting these openings in the pis'- tonto suitable tubes supplying the oil to the various places of oilconsumption. At' the same time the one, two or even more pistons areguided, with regard to their longitudinal movement, with positive motionand we have provided the same with a throw controlling device which isfit and adapted while the pump is in operation, or at rest, to vary thelength of stroke of the pistons and to obtain thereby a faultlessadjustment of the throw and eliminate the usual inconveniences, so thatthe quantity of oil which is being delivered may be so adjusted that itis each time coping with the quantity of oil which is actually required,and which will remain always the same during the whole time the throwcontrolling device is set and adjusted to that particular quantity ofthe supply.

' A particular advantage and an additional characteristic of the presentinvention lies in the location of several pistons in one and the sameaxial direction ofthe same. The pistons are connected by suitablydesigned coupling means with the driving piston, so that only onedriving spindle is needed for moving the totality of the pistons. Theadequately designed and constructed coupling means has for its object toaccomplish any desired variations of the throw, regardless of thecoupling together of the pistons, o that the varying of the throw' ofone of the iistons will not interferezin any way with the other pistons.In this manner there is provided a rotary piston umpl which, with aminimum expenditure ot) material and the smallest admissible numberofcomponent parts, makes use of only one drive and one suction point, andsupplies simultaneously two, three or more oil consuming places withloil, and the whole assembly may be made of such small dimensions thatwhen fitted to 'a motor cycle engine or the like, the accessibility ofthe engine is not impaired.

The invention is illustrated in Figs. 1 to 10 of the accompanyingdrawing, and in which Fig. 1 is a front elevation, Figs. 2 and 4 eachshow a longitudinal view through the pump with the pistons in differentpositions, while Fig. 3 is a cross sectional view of the pump about theline A-B of Fig. 2 and Fig. 5 is a cross sectional view of the pumpabout the line C-D of Fig. 4. Figs. 6-10 are showing various positionsat which the throw controlling device has been set within the grooveswhich are formed in the pistons.

In the embodiment of our invention, which is shown in the drawing, arotary pump with three force points and one throw controller device foreach piston, has been adopted.

is putting in rotation two or three pistons by means of an endless screwand worm gear. 'Ihe bearings of the pistons are closed by screws 5 andthe interposing of a packing 6, so that the pistons on the one hand areprevented from falling out and on the other hand the escape of any oilis prevented. The

there is formed in the iston 3 a slantin anl nular groove 9, in whichengages the t row controlling device which imparts to the piston apositive motion. The piston 3 has the function of sucking the oil whichis flowing from a point of use and passing it to the suction port 10,disposed at the rear of the two pistons (shown by dotted lines in Figs.2 and 4 and .clearly illustrated in Fi 3) through the boring 11 on theVpiston beine' suitably displaced longitudinally towards the right, andon rotating the piston to a still greater extent to force the samethrough the tube 12 into the inspection chamber. From here the oil isagain sucked by the groove 7, provided on the other end of the piston,and isforced into the boring 14, which communicates with the force point15, which is located directly opposite the suction port 10. In thismanner the force feed point 15 may be controlled throughthe inspectionchamber.

The piston 4 is supplyin the force point' 16 with oil, in such a way tat the oil passes from the boring 11 into a longitudinally extendingboring 18. By the boring 18 and the groove 19 on the rlght hand end ofthe piston 4, the oil is sucked in conformity with the throw of thepiston and is delivered to the force point'16.

As a third piston there is provided in the casing 1, the piston 20which, however, is not moved directly by the driving spindle 2 but bythe piston 4, the piston 4 having on thev left hand end a transverselyextendin groove 21, in which enga es a spring 22 whic is provided on therig t hand end of the piston 20. In this manner the piston20 is coupledwith the piston 4 and accomplishes the same rotary motion as the piston4 itself.

The left end of the piston 20 presents the distinctive feature of thatpump in the form of a groove 23, so that the piston 20, in performingthe appropriate motions (rotation and displacement) willsuck the oil bythe boring 24 which communicates with the analogous -longitudinal boring17 which is disposed in front of the piston and forces the oil into theplace of consumption 25. The pistons 4 and 2O are likewise provided withslanting annular grooves 26 and 27 with which engage the controllingdevices by t which on the one hand the pistons are guided In the pumpcasing 1 a driving spindle 2 with positive motion. in their longitudinalmovements and on the other hand are causing the variations in the lengthof their stroke. The two pistons are coupled in such a manner with eachother that the slanting annular grooves 26 and 27 expand parallel 1nrespect to one another and the positive motion and the longitudinaldisplacement of the two pistons incidental thereto, (by reason of theposition of the slanting grooves) are accomplished always in the samedirection and thus the do not work in opposition to each other. he guideofthe slot and key in the coupling need thus only be of the length ofthe stroke of the coupled pistons, because the variation in the length.of the stroke may on the one hand be of such an amount as the availabletotal length of the stroke of istons (if the curve 1s being varied insuc a way that the pump is not delivering any oil the variation of thecurve corresponds to the total length of the stroke) whereby it isobtained that the total length of the two pistons 4 and 20 which arecoupled' with each other will not be excessive. The characterist-i ofthe pump described heretofore are shown in Fig. 2 and present theposition of the pistons after having completed the suction and forcingmotions with the pump Kworking at full capacity in all force points.

In F ig- 4 the corresponding parts of the .Y pump are designated withlike reference numerals, but the positions are dierent from those shownin Fig. 2 which is due partly to the turning movement of half arevolution given to the. pistons and partly to the change 1n theposition of the controlling device (variation in the length of thestroke). The change in the position of the stroke or throw controllingdevice is represented in Figs. 1 and 5.

On the frontal side of the pump casing are fitted in convenient placesfor each piston (3, 4 and 20) pointers 28, 29 and 30, each of them beingarranged on dials 31, 32 and 33, which enables the operator to read olireadily from the scale the variations in the position of the pistons.The pointer 28 indicates the full capacity of the piston 3, while thepointer 29 indicates half the full capacity, and the pointer 30 onlyabout one fourth part of the full capacity of the pistons 4 and 20respec tively. The controlling device .by itself consists in itsinternal construction of a stud 34 which being formed with various stepsis conveniently seated in the casingl and which is provided on one endwith the pointer and on the other end with two'zeurves 35 and 36 which.in the annular grooves (9, 26 and27) o epistons (3,4and20). Thesaidcurves are shaped to orm ellipses and they are positioned with theiraxes at right angles to each other. manner there is 1mparted to theistons the itive motion above mentione with regar to their longitudinalmovements and the rotation of the curves permits the variation of thestroke, through which however, the positive motion is not impaired.(This is described still more in detail hereinafter.) -The rotatedcurves are shown in Fig. 5 in the lower controlling device and areclearly illustrated. The studs 34 of the throw controlling device willthe stud 34 allow rotation by means of the pointer carried by the studand thus the variation of the length of the stroke. Y

In Fig. 4 is shown in the main, apart from' the other component partsofthe pump already mentioned, the change in the position of the twocoupled pistons 4 and 20 relative to each other, this changecorresponding to the variation of the throw represented in Figs. 1 and5. From Fig. 4 it is plainly seen that the guiding of the coupling inthe space '39 is still ample, even in the case of a very large variationof the throw, in order to ensure a faultless transmission of the momentof torsion from the piston 4 to the piston 20, while however, the lengthof the two pistons couled with-each other isV such that the total engthof the pumpremains a reasonable one. It is at once evldent that thepiston 3 by providing similar coupling means, be able to accomplishthetransmission of the moment of torsion to a fourth piston, so that inthis manner a fourth force point may be created. By suitableconstruction of the piston additional pistons may be axially connectedup by means of coup of the kind such as have just been descri all ofwhich, however, can be supplied with oil from one suction point only,and all the pistons can be driven by one and the same spindle (spindle2).

Now, hereinafter is described the special part which characterizes thepump, viz., the throw controlling device with its function and action.The grooves which are formed on the pistons 2, 4 and 20 are formed andarranged in such a way that the groove 40 is drilled in a verticalposition with respect to the axis of the piston, while'the groove 41 isextending in a slantiug position with respect to the The ve 40 isnarrower and deeper 'than Ythe groove 41 and the difference between thewidth of the twoV grooves represents the length of the throw. The wallsof the opposite points of t eir ath with the walls of the groove 41.vThus t e groove 41 consti- -I tutes the throw curve groove. With theseVgrooves 40 and 41 and 41 engage the suitably formed curves (ellipses)and 36 and dis d on the throw controlling member an which are positionedcrosswise to each other, so that the short axis of the ellipf-e axis fthe `ellipse oove meet attwoV to the width of groove 40. Whenever thethrow controlling member 34 with the curves 35 and 36 is placed in sucha position that the large axis of the ellipse 35 is engaging in itsentire length with the walls of the groove 41, the complete stroke ofthe piston will be accomplished by reason of the positive action of thegrooves. The short ellipse 36 engages in the groove 40 (the spacing ofthe ellipse corresponds to the depth of the grooves) but same does notexert any effect because the location and position of the grooves andthe ellipse are such that they cannot counteract or act in opposition tothe normal throw of the piston. L

The maximum quantity which can-be delivered by the pump will be attainedby the position of the curves (ellipses) 35 and 36 which they takebetween the grooves 40 and 41 as is shown in Figs. 6, 7 and 8. Asalready explained the curve 35, inasmuch as the large axis of the sameis in its entire length in engagement with the groove 41, will provide acomplete throw of the piston. How this can be achieved is shown in Figs.6, 7 and 8. After having secured member 34 of the throw controllingdevice both against axial displacement and against rotation, the pistonsare compelled, according to the degree of inclination of groove 41 andof the compulsory guiding means of the curve 35,

to take advantage of the difference between the inclined position of thewalls of the groove 41 and the fixed guiding means 35 for insurin thethrow.

In Fig. 6 the piston is shown in its posi-"- of groove 40 are in contactat the left against the'left hand narrow side of the curve 36. In Fig. 7the piston is shown in its position when displaced completely towardsthe left when the compressing of the walls of the groove towards thecurves takes place in the reverse order to what has been explainedabove. In Fig. 8 is shown the displacement of the piston in anintermediate position and consequently also the intermediate position ofthe curve 36 within .the groove 40. The short axis of the` curve 36therefore corresponds tothe length of the stroke and groove 40 is twiceas wide as the short axis of the ellipse 36. In conformance with thedisplacement of throw of the piston, the large axis of the ellipse ofcurve 35 must be three times as long as the short axis of the curve 36.

In Fig. 9 is shown a slight rotation of the throw controlling member 34.By reason of this rotation it is no longer possible for the completethrow to be accomplished. In this figure is distinctly shown the space42 which is being created between the .curve 35 and the wall of thegroove 41. This space corresponds to the diminution of the throw. If

4the groove 41 will contact with the right hand side of the curve 35,while the left hand wall of the groove 41 will diverge from the curve35. On the other hand, however,

the left hand wall of groove 40 is in contact with the left hand side ofcurve 36, and the right hand wall of the groove is free and presents thespace 43. In rotating the piston through 180 the compression is changedin reverse order. While when the throw controlling member is set in anormal position a fitting or bearing of the wall of the groove 41 takesplace only against the curve 35 the -fitting of the curves 35 and 36with the walls ofh the grooves 40 and 41 will change on rotating thethrow controlling member which of course, is tantamount to a compulsoryguiding also during the variation of the stroke by means of the throwcontrolling member. The variation of the throw and the diminutionof thequantity of oil delivered which is ensuing therefrom, will always'bealike by reason of the compulsory motion and thus the places ofconsumption are supplied always with the same quantity of oil and thatwhich is needed to warrant efficient oiling.

In case the piston 20 for instance should not be needed for oiling, itsthrow may be completely discarded on rotating the throw controllingmember from its full capacity position through an angle of 90 as isshown in Fig. 10. The whole longitudinal axis of the ellipse 36 willspring in its entirety into the groove 40 while the fitting of the curve35 with the walls of the groove 41 will cease.

The piston receives the compulsory motion only through the groove 40extending vertically to the axis of the piston and therefore the pistonremains axially un-displaced although still revolving round Aits axis.

A pump embodying this invention offers considerable advantages overthose of existing types in that it is extremely compact, there are onlya small number-.of simple moving parts, all of which are easy tomanufacv ture, and therefore the utmost reliability is assured.

Variations in the details, when manufacturing the pump, will notinfluence the claims hereinafter set forth, nor will one thereby departfrom the spirit and scope of our present invention.

We claim 1. In a rotary piston pump, a driving member, a primary pistonactuated from said driving member, and secondary pistons actuated forsaid primary piston, and means for varying the stroke of each pistonseparately.

2. In a rotary piston pump, a driving member, a primary piston actuatedfrom said driving member, secondary pistons actuated from said primarypiston, slotand key coupling means between said primary and secondarypistons, and means for varying the stroke of each piston separately.

3. Ina rotary piston pump, a driving member, a primary piston actuatedfrom said driving member, secondary pistons vactuated from said primarypiston, slot and key 'coupling means between said primary andsec ondarypistons, means Jfor varying the stroke of each piston separately, saidmeans comprising grooves in each of said primary or secondary pistons,formed respectively at l right angles and obliquely to the axis of therespective piston, and adjustable studs engaging therewith.

4. In a rotary piston pump a driving member, a primary piston actuatedfrom said driving member, secondary pistons actuated from said primarypiston, slot and key coupling means between said primary and secondarypistons, means for varying the stroke of each piston separately,said\means comprising grooves in each of said primary or secondarypistons, formed respectively at right angles and obliquely to the axisof the respective pistons, and adjustable studs engaging therewith, saidstuds being formed with elliptical bearing surfaces arranged at rightangles to each other, and adapted to engage respectively in lsaidaforementioned grooves. c

HERMANN J OI-IANSON. GEORG KPPEL.

